Spray gun



J. F. SIEFEN SPRAY GUN Jan. 6, 1959 5 Sheets-Sheet 1 Filed May 51, 1956INVENTOR. JOHN F. SIEFEN J. F. SIEFEN Jan. 6, 1959 SPRAY GUN 3Sheets-Sheet 5 Filed May 51, 1956 INVENTOR. 'JOHN F. SIEF'EN UnitedStates Patent-( 2,367 476 SPRAY! GUN 01 1 s sf nrp tmit, M ch-Applicatiou;May 31;1 956; Serial :No.. 588,475v

(c m-s6) My-inventio'n relates to anew.v andtuseful improvement in aspray gunforasp'raying.bufiing compounds, paints; and/ or likematerialin anatornizedrstate.

Spray guns have been developed;which aretcommonly1 referredto asbeingiautomatically operated These auto matic spraynguns are of twogeneral vclasses, butimboth:

classes mechanical or; electrical aircontrolsnare, used;

which are set at an externalpoint generally several feet from the spray;gun. quires acertain length of time, from a ira'ctionvof at This istadisadvantageast it re-HJ secondto two seconds, for the,air.totravellfromthe;

external controlstovthe outlet nozzle, of, thenspraylzgun;

when starting-to spray, and,- als o, ittrequires acertain; length oftime-to, exhaust the air to the stop-9ft: point; whenstopping a sprayingoperation. These ttypes-qofn guns are generally recognized as having;certain idisad-l vantages.

1 ype-o heaforemen io edsprayeuns equi e wo air-hoses to be led to ,thespray gun. Oneqof these ir hoses vfurnishes: air iat anorrnalhighpressure tomQYQ, apiston whichtopens antinternal valve so as to permitair from a secondair hose tqbe deliveredthroughpas sages in the body totheair cap. The second air hose is used fordelive ing atomiz ing airtoatomize; or breaig, into small pa'rtieleethegnaterial being sprayed Thep ton, after traveling a sh r t distance opens a needle valve allowingthesprayed n'iat erial to pass through the fluid, tip

A. second broad classifi cationof spray gunsomjhe, market today usesonef air hose so that thesupply of air regulated atan eiiternal valve,moves; a piston ort dia-,,' phragm to. open the needleavalve, the bodyof thesplray gun this same supply of ai 1s ,used; to atomize'the spraymaterial. This type erally has a spattering of end of each operationwhich. is especially noticeable at-1 the end of the operat on This isdue to thegneedle valve: opening beforenormal atomizing air. pressurehas been; built up'at the air cap and,' on' closing, the atomization,pressure at the cap drdpsbeforeithe needle closes The presentinvention'has as its object the avoidance of these difficulties andvthe,provision of a spray so,

arranged and constructed so that no external aipvalve. to control theair flow is' required as the air control valve is madeas a part of thegun itself. Y Another object of the invention istheprovisiont ofi aspray gun of this cl'ass having a'nair control valve adaptd:tofprovidesubiantially instantaneous opening and clos ing of the valve,atth ebeginning and ,en-d ofwthe operation; Another object of theinvention, ,is 3 the provision, of, a spray guu his WP h in a n'undeProper; pressure for atorniz'atioii' s always present in the, gun so,that the disadvantages referred toflas t o. the sprayed ma; terial maveni Anni 1? Spray, an i i l mifv rgr't' pact.

'," 1. jb nialei r f cin enamia ighly s iqi t in u e a d. ht ndv m Thr uhtpass e tin t of the invention is v the provisiongoh a z fit u ri nrthe, Sprayat t e inn n aa lz 2,867,476 Patented Jan. 6, 1959 ice Otherobjectswill appear hereinafter.

It is recognizeduthatvarious modificationstand changes may. be made inthe v details of the structure illustrated without departingmfromtheinvention, and,it:is iutendeda that-the-prsent disclosure shall beconsideredito: be-.but; the preterrediembodimenu Forming. a.PBIZti'OfzrthiS application aretdrawings ain -i which, n 5

Fig; la'isla side;elevational viewflof the invention;;

Fig.=2-.-is an .endzelevational aviewt'of; the:.invention; I.

Figi 3 'ista: longitudinal central S6Cti0IlBl23ViBW nOfL-thQQL inventionshowing the control parts in one-position-gt.

Fig. .4-is a view.- similar to Fig. 3 :showing the :control parts inanother position;

Fig. 5 is-va fragmentarysectional.view; taken onitlinea .'Of Fig. .31. a

In, thedrawings I havetindicated the, spray. guntlasu. comprising, a boy 15..:hav-ing a, chamber 16 at the; for-H. ward? end vthereoficommunicating through the passagealT with, a fitting -18ntowhich'. a,conduit; maybe; attached; for delivery; Qfi'vthevspray, fluid intotheufchamberhlfig Threaded into the, end of the body is, a nozzle. ,19.having; an outlet; opening ztl and hollow to provide a comparts; dap ed,o: ngage-.1 at; it ndf o lose-w the. outlet; pe n 2.04. t 1 secnredonthe end of the-body 15 by; means of a collar; 4 atai 923; hav pa g s2.5 rme therein; ommu ic tin i ht he utl passag s udal o. QI Ih: s Passaes-M do nwar ly. hrough; e, gr oves 74-1 formed on the conical end 75 ofthe= -nozjz le,1 9;, and outf; ward rl nou h hez nnu art pas a aro ndthe-outlet; sleeve or terrninus zila qof thenozzle- 12; The-air underpressure emits through; passage ,201; 1 to atornizo; thell flu id whihernits fronnopening Zilfllld emits through; passages 2d :t o forrn orshape this atomized fluid stream A nippl e 27; is; adapted for beingconnected to anair hose, so Lthattheair under pressure may be; deliveredinto;

the internal air-passages 28 into tthet cylinder ,29,at; one; sideoftthepiston mr Thi$ P Qn- 3tl isprovided with; a hub .,31;o n{, whi h is.threaded atretainen 32; wh-ic is adaptedto serve as a fi i fl t i hihzwo qsa s; with the send, face ot the; piston-hr); retainthe sealingring 33 in: engagementwith the:bottom of the cy-linder;

29, so as to close coinrnunicatjonlof the space-1,34, which,

surrounds the retainer fill with thetcylinder-29 jThep 0 type. Securedon;theQpposite.;end of the, ho dy 15. 19;

7 means pfthe collar 35isjthefsupport or-retainerfia which islthreadedonto ,a,

The cylinder lfl comrnunicates with the atmosphere by; thefollowing"described conduit means. A chamber 39} is formed in theretainer- 36 and lco-mmunicatesithrough g the passage 40 with thecompartment. 41;; This corni-I, partrnent :41 is, adapted itocommunicate. ethrough uthet passage's eiz and 43 withthe, atmosphere.v w

' A valve head 44 is projectable into the .charnber;. 41 and this .valvehead carriesat its end a composi tiorn disc valve 45 which serves toengage loverv the passage;

42" and close thersarn'e, so that the chamber; 41, i 'theu no longer incornrnu ieationv with the atmosphere, A, bead146 on the valve head 44,en gages one end of,.;the l' t n 1 he a ei fw irh a f l mi a w seat in'the fi ting 3 7 This valve .h e ad .44; is com te of "the solenoid coilI 49 .which ni ay e; electrically connected to ,asourcetof energy by;means} ofgthe, cable QSQ;

Formed in piston 30 ,is.,,a; recess 51;1 in which isg,

3. slidably mounted a pair of spaced apart integral annular flanges 52and 53, carried by the stem of the needle valve 22. A sealing ring 54,preferably one of the type, is positioned between said flanges 52 and'53.v

Acoil spring 55 engages at one end the flange 53 and at its other endthe bottom of the chamber or compartment 39. Embracing this coil spring55 is a coil spring 56 which engages at one end the bottom of thecompartment or chamber 39 and at its opposite end in a recess. 57 formedin the face of the piston 30.

The space 34 surrounding the retainer 32 is in communication with aplurality of passages 58 formed in the body 15. These passages 58communicate With the space 59 which is between the end of the body andthe aircap 23.

In use the spray fluid would always be under pressure, so that in thechamber 21 spray fluid would be ready for emission through the outletopening upon opening of the needle valve 22. This needle valve- 22passes through a packing 60 which may be packed by the gland 61 which isaccessible through the opening 62 formed in the body 15.

gland is provided with a head 63 for the reception of a suitable wrench.As shown in Fig. 3, the needle valve 22 also projects through a sealingring 64, preferably of the 0 type. The sealing ring 64 is seated aroundthe needle 22 in a recess in the face of a collar 64a which is mountedin the recess 64b in the body 15. The sealing ring 64 is operativelyretained in the collar 64a by means of the collar 64c which isthreadably mounted in the body 15. The sealing ring 64 functions as anair seal to prevent air leakage around the needle valve 22 from thechamber 34.

When the spray gun is set up for use, compressed air under pressure willflow through the fitting 27 and the passage 28 into the cylinder 29, atthe right side of the piston 30, as viewed in Figs. 3 and 4, and throughpassage 30a in the piston 30 to that portion of cylinder 29 to the leftof piston 30. As communication of the cylinder 29 at the left of piston30 with the atmosphere through passages 42 and 43 is closed no movementof the piston to the left takes place. Bleed passage 30a is formedthrough piston 30 so that the air pressure on both sides of the piston30 is equalized.

Consequently, the spring 56 will retain the piston 30 in a closed or atrest and, the pressure of the spring 55 will retain the needle valve 22in a closed or at rest position.

A suitable switch would be interposed in the cable 50 and upon closingof this switch and the energizing of the solenoid 49, the armature 48would move to the left, as shown in Fig. 4, so that the composition discvalve 45 would move into an opening position relative to the chamber 41and thus permit communication of the cylinder 29 at the left side ofthepiston 30 with the atmosphere, through passages 42 and 43. This wouldunequalize the air pressure on opposite sides of the piston 30 sothatjsaid piston would move to the left as shown in Fig. 4, so as toestablish communication between the cylinder 29 and the space 34 aroundthe retainer 32. Therefore, the'air in the cylinder 29 would passthrough the space 34 and through the passages 58 to the passages 59, 73,74, 25, 26 and 20b. After the piston 30 has moved to the left a shortdistance it would pick' up and move the needle valve 22 to the left. Inthis movement there would be a lag in said picking up effect,on accountof the gap 51, so that the sealing ring 33 would move to an openposition before theneedle valve 22 moved to open position. Thisflagwould be of very short duration, but, before "tli'e"sp ray fluid wouldissue from the opening 20,fatomizingffair would be issuing through thepassages-"20bnand 26. Consequently, any fluid emitting through theoutlet 20 Willbe immediately'subject'ed to the'air'actionf The packing60 functions as a spray fluid seal to prevent leakage from the chamber16. This position as shown in Fig. 3,

' means communicating In stopping the operation, upon deenergization ofthe solenoid 49, the core 48 would be moved to the right in response tothe spring presure 47, thus cutting ofl? coinmunication of the cylinder29 with the atmosphere. The air pressure on opposite sides of the piston30 would then build up to equal pressures, and the spring 56 would forcethe piston 30 to the right. At the same time, spring 55 would force theneedle valve 22 to the right. After piston 30 and needle valve 22 havemoved to the right a distance equal to the travel distance between theopen position of the needle valve 22 and the closed position of saidneedle valve, the delivery of spray fluid would cease. Piston 30continues moving to the right, on account of gap 51, to its closingposition, cutting off communication of cylinder 29 to space 34 bysealing ring 33. Thus, atomizing air would cease to flow throughpassages 58, 59, 73, 74, 25, 26 and 20b. This time lag on stopping'theoperation would assure that all spray fluid would atomize, as the sprayfluid will cease before atomizing air would cease. rest or closedposition.

In this manner, the various disadvantages and difliculties would,therefore, be overcome and a substantially instantaneously controlledspray would be accomplished.

As shown in Figs. 4 and 5, formed through the body is a passage 76through which may be extended a stud 77 which threads into a stem'78 ofa yoke embodying :the separated arms 79 and 80 of Fig.v 2, which may bedrawn together by a suitable screw 81 so that the arms 79 and 80 mayclamp against a suitablesupport or rod which may be projected throughthe opening 82, thus affording a means of mounting the gun in stationaryposition when desired.

What I claim is:

1. A spray gun of the class-described, comprising: a body; an outletnozzle mounted on one end of said body and havin'gan outlet opening forthe emission of liquid therefrom; a cylinder on the opposite end of saidcompartment with the atmosphere; a valve in said compartment for closingcommunication between said passages; a piston slidably mounted in saidcylinder; a spring in said cylinder normally urging said piston in onedirection; an inlet port in said body communicating with said cylinderat one side of said piston for conduct ingair under pressure thereinto,and moving said piston. in the opposite direction against thecompression of said spring; an inlet port in said body for conductingliquid under pressure into said body for emission through the outletopening of the said nozzle; a rod in said body having a needle valve atone end for engaging said nozzle op osite end extending through saidpiston;. and, an. enlargement on said rod engageable with said piston,upon movement of said pistonagainst the compression of said spring aslight distance for engaging said needle valve and moving said needlevalve to open position.

2. A spray gun of the class described, comprising: a body; an outletnozzle mounted on one end of said body and having an outlet opening forthe emission of liquid therefrom; a cylinder on the'opposite end of saidbody; a retainer mounted on said opposite end of said body and forming aclosure for said cylinder and having conduit said cylinder with theatmosphere; said conduit means including a compartment, a first passagecommunicating said compartment with said cylinder, and a'second passagecommunicating said comment for closing communication a piston slidablymounted said The spray gun is now at and closing said. outlet opening;said rod at its in said cylinder normally-t urging-said pistonfin; one

direction; an inletport in saidv body ;cornmunic ating with saidcylinder at one vside of said piston for. conducting air under pressurethereinto, and moving said piston in v the opposite direction againstthe compression of said first spring; an inletflport in said bodyQforconducting liquid under pressure into said body for; emission through ithe outlet opening of the said nozzle ,a rod in saidgbody havinga needlevalve at one end for engaging. said nozzle and closing said outletopening said rod at its opposite I and having an outlet opening for theemission of liquid 7 therefrom; a cylinder on, the opposite; end of saidbody; a retainer mounted on said opposite endof said body and forming aclosure for said cylinder and having conduit means communicating saidcylinder With the ;atmos-.

phere; said conduit means including a compartment, a first passagecommunicating with said compartment with said cylinder, and a secondpassage communicating said compartment with the atmosphere; a valveinsaid compartment for closing communication between said passages; 7

a piston slidably mounted in said cylinder; a first spring 2 fj ld. r ss ri having a needle. valve at one end tor engaging rsaid -no zle andclosing saidoutlet opening; said than; site vend extending through saidpiston; an nlarg'ement on saidrod engageable with saidvpistonuponrniovemel H of said piston against the compression of said firstspring a slight distance for engaging saidneedleyalveandln o ing saidneedle valve. to open'position;ia seeondspring extending into saidcylinder andengaging at one endQs'aidQ. retainer and at the opposite endsaid'enlargement on sa' rod for normally urging said needle .valve tintoclosing position; said piston-havinga passage fornred. the through foreffecting'equalizing of lair 'rjessure I site sides of said piston; and,a solenoid in. saidretainer for, upon being energized opening said firstn med eval and establishing communicjation of sar cyl der at o side ofsaid piston with the atmosphere,

5. A spray gun of the 'classdeseribed, cornprisingzoa body; an outletnozzle mounted. on one end,.of

and having an .outlet opening' ferr the lemiss io n of -ligui therefrom;a cylinder on the opposit e end-pf said body a retainer mounted on'saidopposite end oflsaid body an forming a closure for said cylinder andhaving pondui means communicating saidcylinder with the atmosphere saidconduit meansinclu'ding. ai'cornpartment a firs passage communicatingsaid compartrnent with said cylinder, and a second passage communicatingsaid vcompartment with the atmosphere; await/ .in .said compartment;

in said cylinder normally urging said piston in one.di-

rection; aninlet port in said body communicating with said cylinder atone side of .saidpiston for conducting airunder pressure thereinto, andmoving said piston in theopposite direction against the compression ofsaid firstispring, an inlet port in said body for conducting liq-. uidunder pressure into said body, for emission through the outlet openingofthe saidnozzle; a rodin said body having a needle valve at one end forengaging said nozzle and closing said outlet opening; said rod at itsopposite end extending through-said, piston; an enlargement on said rodengageable withsaidpiston, uponmovement of said piston against thecompression of saidfirst spring a slight distance for engaging saidneedle valve and moving said needle valve to open position; a secondspring extending into said cylinder. and engaging at one end saidretainer and atthe opposite end said enlargementon said rod for,normally urging said needle valve into closing position; and, saidpiston having a passage termed therethrough for effecting equalizing ofair pressure on opposite sides of said piston.

4. A spray gun of the class described,'cornprising: a body; anoutletnozzle mounted on one end of said body and having an outlet openingforthe emission of liquid therefrom; a .cylinder on the opposite end ofsaid body; a retainer mounted on said opposite end of said body andforming a closure torsaid cylinder and having con duit meanscommunicating said cylinder with the atmosphere; said conduit meansincluding a compartment, a first passage communicating said compartmentwith said cylinder, and a segond passagecommunicating saidcom partmentwith the atmosphere; a valve in said compartment for closingcommunication between said passages; a piston slidably mounted in saidcylinder; a first spring in said cylinder normally urging said piston inone direction; an inlet port in said body communicating with saidcylinder at one side of said piston for conducting air under pressurethereinto, and moving said piston in the opposite direction against thecompression of said first spring; an inlet port in said body forconducting liquid under pressure into said body for emission through theoutlet opening of the said nozzle; a rod in said body for closingcommunication betweensaid passages; a piston slidably mounted in saidcylinderfya first springdn said cylinder normally urging said piston inonedirection; an inlet port in said body communicating iwith saidcylinder at one side of said piston for. conducting. an under pressurethereinto, and moving said piston in the ppp'osite di rection againstthe compressionfof'said firstssp ring; an inlet port in said body forconducting lliquid under pres-, sure into said body for emissiontliroughthe outlet opening of the said nozzle; a rod in said body having aneedle valve at one end for engaging said nozzle and closing sai Y 1outlet opening; said rod .at its opposite end extending through saidpiston; an enlargement on said rod engage; able with said piston, uponmovement of said. piston against the compression of said ffirst fspringa slight dis-t tance for engaging said needle valve and moving saidneedle valve to open. position;,a second spring extending into saidcylinder and engaging at one end said retainer and at the opposite endsaid enlargement on said rodjfo normally urging said needle valve intoclosing position; said piston having a passage formedtherethroughfioreffecting equalizing of air pressurefon opposite: sides of} said piston;a passage in said body for deliveringair from said cylinder to anda'ro'un'd said nozzle; and,v avalve on said piston for controlling conimunicationof saidllast named passage with said cylindefandmovable toopen position upon movementlof saidipiston againstfme cornpression ofthe first spring bearing fjagainstfthe same; I

6. A spray gun of the class described; compris'in'gz a 3 body; an outletnozzlemounted .onone'end .of saidbody andhaving an outlet opening forthe emission of liquid therefrom; a cylinder on the opposite end of saidbody; a retainer mounted on .said opposite end of vsaidflbody f andforming a closure for said cylinderan'dhav'ing con- 1 duit meanscommunicating' said cylinder with the 'atrnos phere; said conduit medias includingiaeornpartrnent a first passage communicating saiddepartment's/ahead cylinder, and a second passage communicating saidcompartment with the atmosphere; a valve in said compart ment forclosing communication between said passages; a piston slidably mountedin said cylinder; a first spring in said cylinder normally urging saidpiston in one direction; an inlet port in said body communicating withsaid cylinder at one side of said piston for conducting air underpressure thereinto, and moving said piston in the opposite directionagainst the compression of said first spring; an inlet port in said bodyfor conducting liquid under pressure into said body for emission throughthe outlet opening of the said nozzle; a rod in said body having aneedle valve at one end'for engaging. said nozzle and closing saidoutlet opening; said rod at its opposite end extending through saidpiston; a recess in said piston having an inner end face; an enlargementon said opposite end of the rod and being seated in said recess inspaced relation from said recess end face when the needle valve is inthe position to close the outlet opening; said enlargement on said rodbeing engageable with said recess end face in said piston, upon movementof said piston against the compression of said first spring aslightrdistance for engaging said needle valve and moving said needlevalve to open position; a second spring extending into said cylinder andengaging at one end said retainer and at the opposite end saidenlargement on said rod for normally urging said needle valve intoclosing position; said piston having a passage formed therethrough foreffecting equalizing of airpressure on opposite sides of said piston; apassage in said body for delivering air from said cylinder to and aroundsaid nozzle; and, a valve on said piston for controlling communicationof said last named passage with said cylinder and movable to openposition upon movement of said piston against the compression of thefirst spring bearing against the same.

7. A spray gun of the class described, comprising: a body; an outletnozzle mounted on one end of said body and having an outlet opening forthe emission of liquid therefrom; a cylinder on the opposite end of saidbody; a retainer mounted on said opposite end of said body and forming aclosure for said cylinder and having conduit means communicating saidcylinder with the atmosphere;

said conduit means including a compartment, a first passagecommunicating said compartment withsaid cylinder, and a second passagecommunicating said compartment with the atmosphere; a valve in saidcompartment for closing communication between said passages; a

solenoid connected to said valve for controlling the same and upon beingenergized, moving said valve to an open position for establishingcommunication between said passages; a piston slidably mounted'in saidcylinder; a first spring in said cylinder normally urging said piston inone direction; an inlet port in said body communicating with saidcylinder at one side of said piston for conducting air under pressurethereinto, and moving said piston in the opposite direction against thecompression of said first spring; an inlet port in said body forconducting liquid under pressure into said body for emission through theoutlet opening of the said nozzle; a rod in said body having a needlevalve at one end for engaging said nozzle and closing said outletopening; said rod at its opposite end extending through said piston; anenlargement on said rod engageable with said piston, upon movement ofsaid piston against the compression of said first spring a slightdistance for engaging said needle valve and moving said needle valve toopen position; a second spring extending into said cylinder and engagingat one end said retainer and at the opposite end said enlargement onsaid 1 rod; for normally urging said needle valve into closing position;said piston having a passage formed there-,

through for effecting equalizing of air pressure on oppdsite sides ofsaid piston; a nozzle cap mounted on said body and embracing said outletnozzle and having air passages formed therein for discharging airoutwardly around said outlet nozzle in the path of flow of liquidpassing through said outlet nozzle; a passage in said body fordelivering air from said cylinder to the passages in said nozzle cap;and, a valve on said piston for controlling communicationof said passagein said body with said cylinder and movable to open position uponmovement of said piston against the compression of the first springbearing against the same.

8. A spray gun of the class described, comprising: a body; an outletnozzle mounted on one end of said body and having an outlet opening forthe emission of liquid therefrom; a cylinder on' the opposite end ofsaid body; a retainer mounted on said opposite end of said body andforming a closure for said cylinder and having conduit meanscommunicating said cylinder with the atmosphere; said conduit meansincluding a compartment, a first passage communicating said compartmentwith said cylinder,

and a second passage communicating said compartment with the atmosphere;a valve in said compartment for closing communication between saidpassages; a solenoid connected to said valve for controlling the sameand upon being energized, moving said valve to an open position forestablishing communication between said passages; a piston slidablymounted in said cylinder; a first spring in said cylinder normallyurging said piston in one direction; an inlet port in said bodycommunicating with said cylinder at one side of said piston forconducting air under pressure thereinto, and moving said piston in theopposite direction against the compression of said first spring; aninlet port in said body for conducting liquid under pressure into saidbody for emission through the outlet opening of the said nozzle; a rodin said body having a needle valve-at one end for engaging said nozzleand closing said outlet opening; said rod at its opposite end extendingthrough said piston; a recess in said piston having an inner end face;an enlargement on said opposite end of the rod and being seated in saidrecess in spaced relation from said recess end face when the needlevalve is in the position to close the outlet opening; said enlargementon said rod being engageable with said recess end face in said piston,upon movement of said piston against the compression of said firstspring a slight distance for engaging said needle valve and moving saidneedle valve to open position; a second spring extending into saidcylinder and engaging at one end said retainer and at the opposite endsaid enlargement on said rod for normally urging said needle valve intoclosing position; said piston having a passage formed therethrough foreffecting equalizing of air pressure on opposite sides of said piston; anozzle cap mounted on said body and embracing said outlet nozzle andhaving air passages formed therein for discharging air outwardly aroundsaid outlet nozzle in the path of flow of liquid passing through saidoutlet nozzle; a passage in said body for delivering air from saidcylinder to the passages in said nozzle cap; and, a valve on said pistonfor controlling communication of said passage in said body with saidcylinder and movable to open position'upon movement of said pistonagainst the compression of the first spring bearing against the same.

References Cited in the file of this patent Carr May 15, 1951

